Numeja 
Parse numbers in japanese numerals from String
漢数字とかをInteger or Floatに変換するGem
Installation
Add this line to your application's Gemfile:
gem 'numeja'And then execute:
$ bundle
Or install it yourself as:
$ gem install numeja
Usage
require 'numeja'
Numeja.numerize('二千三百八十一億九千四百八十七万六千三百十一') # => 238_194_876_311
Numeja.numerize('弐阡參佰捌拾壱億九千四百八十七万六千三百十一') # => 238_194_876_311
Numeja.numerize('9876億5432万1千2百3十4') # => 987_654_321_234)
Numeja.numerize('９８７６億５４３２万１千２百３十４') # => 987_654_321_234
Numeja.numerize('玖阡捌陌漆拾陸億伍仟肆佰參十貳万壹千弐百卅４') # => 987_654_321_234
Numeja.numerize('５０５') # => 505
Numeja.numerize('九八七六五四三二一零') # => 9_876_543_210
Numeja.numerize('九分八厘七毛六糸五忽四微三繊二沙零塵一埃') # => 0.9876543201
Numeja.numerize('九割八分七厘六毛五糸四忽三微二繊零沙一塵') # => 0.9876543201
Numeja.numerize('二分の一') # => 0.5
Numeja.numerize('三分の一') # => 0.33333333333...